Patent GB-411158-A (GB)
Title: A process for the conversion of unsaturated hydrocarbons into high grade non-oxidising lubricating oils, transformer oils and like oils
Filed: 1932-12-02
Abstract: The products obtained by cracking hydrocarbons, preferably in the vapour phase, are distilled to separate fractions which do not yield nonoxidizing oils on polymerization, nonoxidizing oils being defined as oils which, after subjection to a specified resinification test, yield less than 10 per cent by weight of asphaltenes, calculated on the resinification residue.  The remaining fractions are then polymerized, wholly or in part, by treatment with suitable reagents such as sulphuric or phosphoric acid or aluminium chloride.  Products useful as lubricating oils or transformer oils are obtained.  When the cracking products contain sulphur, the fractions which do not yield nonoxidizing oils on polymerization are generally those of higher sulphur content; the rejected fractions also have, as a rule, a higher content of aromatics than the other fractions.  The whole of the cracking products, or the fractions selected for polymerization, may be purified by a preliminary polymerization followed if necessary by treatment with alkali lye.  In the examples: (1) particulars are given of the relative stability to oxidation of the products obtained by polymerizing with aluminium chloride a vapour-phase cracking benzine and fractions taken therefrom, only the fraction boiling between 165 and 175 DEG  C. yielding nonoxidizing oils; (2) a fraction boiling up to 160 DEG  C. of a vapour-phase cracking benzine is treated with sulphuric acid, and the fraction of the product boiling between 135 and 155 DEG  C. is polymerized with aluminium chloride to yield a nonoxidizing oil.  Reference is made also to the polymerization of sulphur-free benzines to which small amounts of organic sulphur compounds such as thiophene, amyl mercaptan, amyl sulphide, propyl mercaptan, or thiophene have been added, with a view to establishing the point that organic sulphur compounds adversely affect the polymerization process. Specification 399,646 is referred to.ALSO:The products obtained by cracking hydrocarbons, preferably in the vapour phase, are distilled to separate fractions which, on polymerization, yield oils susceptible to oxidation, and the remaining fractions are then polymerized, wholly or in part, by treatment with suitable reagents such as sulphuric or phosphoric acid or aluminium chloride.  Oils of high stability to oxidation are obtained.  When the cracking products contain sulphur, the fractions unsuitable for polymerization are generally those of higher sulphur content; the rejected fractions also have as a rule, a higher content of aromatics than the other fractions.  The whole of the cracking products, or the fractions selected for polymerization, may be purified by a preliminary polymerization followed if necessary by treatment with alkali lye.  In the examples: (1) particulars are given of the relative stability to oxidation of the products obtained by polymerizing with aluminium chloride a vapour-phase cracking benzine and fractions taken therefrom, only the fraction boiling between 165 and 175 DEG  C. yielding relatively nonoxidizing oils; (2) a fraction boiling up to 160 DEG  C. of a vapour-phase cracking benzine is treated with sulphuric acid, and the fraction of the product boiling between 135 and 155 DEG  C. is polymerized with aluminium chloride to yield an oil of high stability to oxidation. Reference is made also to the polymerization of sulphur-free benzines to which small amounts of organic sulphur compounds such as thiophene, amyl mercaptan, amyl sulphide, propyl mercaptan, or thiophene have been added, with a view to establishing the point that organic sulphur compounds adversely affect the polymerization process.  Specification 399,646 is referred to.